Contributing
Introduction
Join LVGL's community and leave your footprint in the library!
There are a lot of ways to contribute to LVGL even if you are new to the library or even new to programming.
It might be scary to make the first step but you have nothing to be afraid of. A friendly and helpful community is waiting for you. Get to know like-minded people and make something great together.
So let's find which contribution option fits you the best and help you join the development of LVGL!
Ways to contribute
Spread the Word: Share your LVGL experience with friends or on social media to boost its visibility.
Star LVGL Give us a star on GitHub ! It helps a lot to LVGL more appealing for newcomers.
Report a bug: Open a GitHub Issue if something is not working.
Join our Forum : Meet fellow developers and discuss questions
Tell your ideas: If you miss something from LVGL we would love to hear about it in a GitHub Issue
Develop features: Help to design or develop a feature. See below.
Mid and large scale issues are discussed in Feature planning issues.
An issue can be developed when all the questions in the issue template are answered and there is no objection from any core member.
We are using GitHub Labels to show the state of the issue:
planning
: Still discussing how to approach it.outlined
: We have come to a conclusion and the feature is ready to be developed.request-change(<user-name>)
: Each core member has a dedicated label, and when they request a change, they add their label.under development
: It's being developed by someone (can be developed only if no change is requested by the end of the cool-down phase).ready
: The pitch is developed and merged into master.stale
: Inactive, can be warmed up.rejected
: Not interested in this feature for some reason.
Pull request
Merging new code into the lvgl, documentation, blog, examples, and other repositories happen via Pull requests (PR for short). A PR is a notification like "Hey, I made some updates to your project. Here are the changes, you can add them if you want." To do this you need a copy (called fork) of the original project under your account, make some changes there, and notify the original repository about your updates. You can see what it looks like on GitHub for LVGL here: https://github.com/lvgl/lvgl/pulls.
To add your changes you can edit files online on GitHub and send a new Pull request from there (recommended for small changes) or add the updates in your favorite editor/IDE and use git to publish the changes (recommended for more complex updates).
From GitHub
Navigate to the file you want to edit.
Click the Edit button in the top right-hand corner.
Add your changes to the file.
Add a commit message on the bottom of the page.
Click the Propose changes button.
From command line
The instructions describe the main lvgl
repository but it works the
same way for the other repositories.
Fork the lvgl repository. To do this click the "Fork" button in the top right corner. It will "copy" the
lvgl
repository to your GitHub account (https://github.com/<YOUR_NAME>?tab=repositories
)Clone your forked repository.
Add your changes. You can create a feature branch from master for the updates:
git checkout -b <the-new-feature-branch-name>
Commit and push your changes to the forked
lvgl
repository.Create a PR on GitHub from the page of your
lvgl
repository (https://github.com/<YOUR_NAME>/lvgl
) by clicking the "New pull request" button. Don't forget to select the branch where you added your changes.Set the base branch. It means where you want to merge your update. In the
lvgl
repo both the fixes and new features go tomaster
branch.Describe what is in the update. An example code is welcome if applicable.
If you need to make more changes, just update your forked
lvgl
repo with new commits. They will automatically appear in the PR.
Commit message format
The commit messages format is inspired by Angular Commit Format.
The following structure should be used:
<type>(<scope>): <subject>
<BLANK LINE>
<body>
<BLANK LINE>
<footer>
Possible <type>
s:
fix
bugfix in the source code.feat
new featurearch
architectural changesperf
changes that affect the performanceexample
anything related to examples (even fixes and new examples)docs
anything related to the documentation (even fixes, formatting, and new pages)test
anything related to tests (new and updated tests or CI actions)chore
any minor formatting or style changes that would make the changelog noisy
<scope>
is the module, file, or sub-system that is affected by the
commit. It's usually one word and can be chosen freely. For example
img
, layout
, txt
, anim
. The scope can be omitted.
<subject>
contains a short description of the change:
use the imperative, present tense: "change" not "changed" nor "changes"
don't capitalize the first letter
no dot (
.
) at the endmax 90 characters
<body>
optional and can be used to describe the details of this
change.
<footer>
shall contain
the words "BREAKING CHANGE" if the changes break the API
reference to the GitHub issue or Pull Request if applicable.
Some examples:
fix(img): update size if a new source is set
fix(bar): fix memory leak The animations weren't deleted in the destructor.
Fixes: #1234
feat: add span widget
The span widget allows mixing different font sizes, colors and styles. It's similar to HTML <span>
docs(porting): fix typo
Developer Certification of Origin (DCO)
Overview
To ensure all licensing criteria are met for every repository of the LVGL project, we apply a process called DCO (Developer's Certificate of Origin).
The text of DCO can be read here: https://developercertificate.org/.
By contributing to any repositories of the LVGL project you agree that your contribution complies with the DCO.
If your contribution fulfills the requirements of the DCO no further action is needed. If you are unsure feel free to ask us in a comment.
Accepted licenses and copyright notices
To make the DCO easier to digest, here are some practical guides about specific cases:
Your own work
The simplest case is when the contribution is solely your own work. In this case you can just send a Pull Request without worrying about any licensing issues.
Use code from online source
If the code you would like to add is based on an article, post or comment on a website (e.g. StackOverflow) the license and/or rules of that site should be followed.
For example in case of StackOverflow a notice like this can be used:
/* The original version of this code-snippet was published on StackOverflow.
* Post: http://stackoverflow.com/questions/12345
* Author: http://stackoverflow.com/users/12345/username
* The following parts of the snippet were changed:
* - Check this or that
* - Optimize performance here and there
*/
... code snippet here ...
Use MIT licensed code
As LVGL is MIT licensed, other MIT licensed code can be integrated without issues. The MIT license requires a copyright notice be added to the derived work. Any derivative work based on MIT licensed code must copy the original work's license file or text.
Use GPL licensed code
The GPL license is not compatible with the MIT license. Therefore, LVGL can not accept GPL licensed code.